Minimum frequency for epcs1 device

[Altera_Forum]

Hi, 

   I'm using the epcs1 configuraion device, in active serial mode. In its datasheet from October 2008, it is mentioned that the minimum frequency for working with the device in Write Bytes operation is 10MHz (table 4-26). They removed it in the datasheet from December 2009. I have a problem writing steadily to the device (sometimes I read the data form that address and sometimes 0xFF). Has anyone come across such a problem? Can the epcs1 serial flash work in, say, 5MHz?       Thanks, Eldad

[Altera_Forum]

I don't have a datasheet containing this obviously confused information (it's neither in the 2007 nor the recent release). Basically SPI flash operation is fully static. 

 P.S.: I would rather expect a problem in performing the serial flash protocol correctly. Generally, writing "steadily" should consider the device's limited endurance and also the necessity of erasing pages before writing to them.